Active cathode temperature control for metal-air batteries

ABSTRACT

A metal-air battery is disclosed, including a cathode temperature controller that identifies a power-boosted operating temperature at which a projected power boost exceeds a projected battery lifetime penalty and a temperature regulator that adjusts the cathode temperature to the power-boosted operating temperature using power generated by the metal-air battery when the metal-air battery is in a discharge state.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and/or claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Priority Applications”), if any, listed below(e.g., claims earliest available priority dates for other thanprovisional patent applications or claims benefits under 35 USC §119(e)for provisional patent applications, for any and all parent,grandparent, great-grandparent, etc. applications of the PriorityApplication(s)). In addition, the present application is related to the“Related Applications,” if any, listed below.

Priority Applications

NONE

Related Applications

U.S. patent application Ser. No. ______, entitled CATHODE TEMPERATUREREGULATION FOR METAL-AIR BATTERIES, naming William D. Duncan andRoderick A. Hyde as inventors, filed 17 Jul. 2013 with attorney docketno. 46076/127, is related to the present application.

The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation, continuation-in-part, or divisional of a parentapplication. Stephen G. Kunin, Benefit of Prior-Filed Application, USPTOOfficial Gazette Mar. 18, 2003. The USPTO further has provided forms forthe Application Data Sheet which allow automatic loading ofbibliographic data but which require identification of each applicationas a continuation, continuation-in-part, or divisional of a parentapplication. The present Applicant Entity (hereinafter “Applicant”) hasprovided above a specific reference to the application(s) from whichpriority is being claimed as recited by statute. Applicant understandsthat the statute is unambiguous in its specific reference language anddoes not require either a serial number or any characterization, such as“continuation” or “continuation-in-part,” for claiming priority to U.S.patent applications. Notwithstanding the foregoing, Applicantunderstands that the USPTO's computer programs have certain data entryrequirements, and hence Applicant has provided designation(s) of arelationship between the present application and its parentapplication(s) as set forth above and in any ADS filed in thisapplication, but expressly points out that such designation(s) are notto be construed in any way as any type of commentary and/or admission asto whether or not the present application contains any new matter inaddition to the matter of its parent application(s).

If the listings of applications provided above are inconsistent with thelistings provided via an ADS, it is the intent of the Applicant to claimpriority to each application that appears in the Priority Applicationssection of the ADS and to each application that appears in the PriorityApplications section of this application.

All subject matter of the Priority Applications and the RelatedApplications and of any and all parent, grandparent, great-grandparent,etc. applications of the Priority Applications and the RelatedApplications, including any priority claims, is incorporated herein byreference to the extent such subject matter is not inconsistentherewith.

BACKGROUND

Power management for metal-air batteries can be complicated. Typically,power generation in a metal-air battery is strongly correlated with thecatalytic processes at the cathode. Catalytic cycles may be affected bymicroscopic-level considerations, such as pore diffusion and catalyticactive site activity, as well as bulk-scale considerations, such astemperature and pressure. Consequently, smooth, steady-state powerdelivery can be challenging during transient periods of batteryoperation and environmental change.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective cutaway view showing an embodiment of ametal-air battery having a power cell and a cathode temperatureregulator, energized by the power cell, for adjusting a temperature ofthe power cell cathode.

FIG. 1A is an enlarged fragmentary view of the power cell cathode shownin FIG. 1 showing an air-permeable catalyst support decorated with anoxygen-reduction catalyst.

FIG. 2 is a schematic view of an embodiment of a cathode temperatureregulator for use with a metal-air battery.

FIG. 3A is a portion of a flow chart for an embodiment of a method ofadjusting the temperature of a metal-air battery power cell cathodeusing power collected from the power cell.

FIG. 3B is another portion of the flow chart shown in FIG. 3A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A metal-air battery is an electrochemical power cell that includes ametal anode and an air permeable cathode. Metal-air batteries may beused in a wide variety of power storage applications, ranging from powergeneration applications (e.g., grid storage for wind farms), tovehicular use applications (e.g., automotive and locomotive), andportable electronic device applications (e.g., cell phones, mobiledevices, and tablet computers).

The rate of electric power generation in a metal-air battery generallyis positively correlated with the rate of a catalytic reaction at anoxygen-reduction catalyst in the cathode. Put another way, an increasein the rate of the catalytic reaction increases the rate at whichelectrons are liberated from the anode.

Some previous metal-air batteries have used externally powered heatersto alter chemical reactions at the cathode. However, external powersupplies can be cumbersome, potentially adding weight and complexity.Moreover, thermal feedback mechanisms within the power cell can damagethe catalyst. Excessive heat may sinter the catalyst particles,potentially reducing the catalytic activity of the cathode. Accordingly,embodiments of methods for adjusting the temperature of the cathode of ametal-air battery using current generated by the battery are disclosedherein.

FIG. 1 is a perspective cutaway view showing an embodiment of ametal-air battery 100 having a power cell 102. Power cell 102 includes ametal anode 104 separated from an air-permeable cathode 106 by anelectrolyte-permeable battery separator 108. During discharge, anode 104is oxidized, forming metal cations and electrons. In some embodiments,anode 104 consists essentially of a pure metal. Non-limiting examplesinclude alkali metals (e.g., lithium (Li) and sodium (Na)), alkalineearth metals (e.g., beryllium (Be) and calcium (Ca)), transition metals(e.g., iron (Fe), manganese (Mn), titanium (Ti), and zinc (Zn)), andGroup 13 metals (e.g., aluminum (Al)).

An electrolyte 110 (e.g., a liquid or a solid-state materialelectrochemically coupling anode 104 with cathode 106) transports themetal cations across battery separator 108 to cathode 106. Batteryseparator 108 is positioned between and electrically isolates anode 104from cathode 106 and is permeable to metal cations and to electrolyte110. In some embodiments, battery separator 108 may include a polymermembrane that is selectively permeable to electrolyte 110, but thatotherwise electrically isolates anode 104 from cathode 106 to preventinternal short-circuiting of power cell 102.

Cathode 106 is porous, so that air permeating the cathode is exposed toactive sites of an oxygen-reduction catalyst therein to promote thereduction of oxygen from the air by metal cations to form a metal oxide.For example, FIG. 1A is an enlarged fragmentary view of cathode 106showing an air-permeable porous catalyst support 112 decorated with anoxygen-reduction catalyst 114. In some embodiments, catalyst support 112may include porous carbon or porous metal oxide materials. In someembodiments, oxygen-reduction catalyst 114 may consist essentially of apure metal catalyst. In some embodiments, oxygen-reduction catalyst 114may include transition metal catalysts (e.g., manganese, cobalt (Co),ruthenium (Ru), platinum (Pt), silver (Ag), and/or gold (Au)).

The rate of a catalytic reaction at oxygen-reduction catalyst 114 ispositively correlated with the rate of power generation in power cell102. Thus, an increase or decrease in power generation may be achievedby heating or cooling cathode 106, and thus, catalyst 114, respectively.A temperature regulator 116 controls the temperature of cathode 106 byregulating heat exchange between cathode 106 and a heat transferstructure 118, described in more detail below. The energy used bytemperature regulator 116 to adjust the temperature of cathode 106 issupplied by power cell 102. Put another way, during discharge of powercell 102, a portion of the current gathered from power cell 102 is usedto power a heat exchange between cathode 106 and heat transfer structure118, subject to regulation by temperature regulator 116.

Temperature regulator 116 adjusts the temperature of cathode 106 withreference to temperature data about cathode 106, and by extension,temperature information about catalyst 114. In the embodiment shown inFIG. 1 a cathode temperature sensor 120 is in thermal communication withcathode 106. In some embodiments, cathode temperature sensor 120 mayinclude one or more bi-junction thermocouples located on and/or withincathode 106 to collect and transmit cathode temperature information totemperature regulator 116. For example, temperature sensor 120 mayinclude an array of spaced apart temperature probes positioned onexterior surfaces of cathode 106 and/or buried within cathode 106 tomeasure the temperature of catalyst support 112 or catalyst 114, or bothof them, and/or to measure the temperature of air in a pore or voidwithin catalyst support 112.

FIG. 2 is a schematic view of an embodiment of temperature regulator116. In the embodiment shown in FIG. 2, cathode temperature data fromtemperature sensor 120 (FIG. 1) is received at a cathode temperaturesensor input 202 in operative communication with a temperaturecontroller 204. Temperature controller 204 also receives currentsupplied from power cell 102 (FIG. 1) through a current input 206,providing power to operate temperature regulator 116 and adjust thetemperature of cathode 106 (FIG. 1) as well as providing batteryelectrical data, such as battery capacity, battery load current, andbattery voltage information.

In the embodiment shown in FIG. 2, temperature controller 204 isinstantiated (e.g., as software) in a data subsystem 206 that holdsinstructions executable by a processing subsystem 208 to operate, on ageneral level, temperature regulator 116. Data subsystem 206 may includeany suitable hardware (e.g., solid state memory in one non-limitingexample) for storing non-transitory instructions used by processingsubsystem 208 (e.g., a logic processor in one non-limiting example) toperform the methods and algorithms and operate the hardware describedherein. The boundary between hardware and software shown in FIG. 2 isprovided only for illustrative purposes, and skilled persons willrecognize that embodiments having other suitable divisions (if anydivision is provided at all) are possible.

In the embodiment of temperature regulator 116 shown in FIG. 2, batteryelectrical data and cathode temperature data are provided to anadjustment algorithm 208 for determining a new temperature for cathode106 using power collected from power cell 102 (FIG. 1). Optionally,temperature controller 204 may include one or more process optimizationalgorithms 210 used to optimize a variable (e.g., a cathode temperatureset point), including various linear and/or non-linear searchtechniques; one or more theoretically or empirically based processcontrol models 214 used to operate and regulate a temperature controlleroutput in response to a given input (e.g., in response to a cathodetemperature set point, select proportional, integral, and derivativeparameters to control cathode temperature to the set point); and/or adata history 216 including past battery data (e.g., data measurementsand process control calculations).

Once the new temperature is identified by adjustment algorithm 208, itis used to operate temperature regulator 116 or heat transfer structure118. In the embodiment shown in FIG. 1, heat transfer structure 118 isdepicted as a solid phase thermal conductor in thermal contact withexterior sidewalls of cathode 106. While the embodiment of heat transferstructure 118 shown in FIG. 1 is in thermal contact with outer exteriorwalls of cathode 106, skilled persons will recognize that heat transferstructure 118 may envelope and/or penetrate cathode 106 in myriadarrangements to exchange heat therewith. Solid phase thermal conductorsmay be capable of actively (e.g., via thermoelectric heat transferand/or resistive heat transfer) or passively (e.g., via a heat pipeand/or a refrigerated or heated non-electrolyte heat transfer fluid flowsystem) exchanging heat with cathode 106. In some embodiments, a singleheat transfer structure 118 may include both heating and coolingelements. In some other embodiments, several heat transfer structures118 may heat and/or cool cathode 106 separately.

In the embodiment shown in FIG. 1, heat exchange structure 118 issupplied with energy from temperature regulator 116 using a conduit 122.Conduit 122 may include convective or conductive heat transfermechanisms (e.g., heat pipes or heat exchange fluid pipes) or electricalheat transfer mechanisms (e.g., current). Regardless of how energy issupplied to heat exchange structure 118, the energy is generated bypower cell 102 and regulated by temperature regulator 116.

FIGS. 3A and 3B are a flow chart for an embodiment of a method 300 foradjusting the temperature of a metal-air battery power cell cathodeusing power collected from the power cell. Skilled persons willappreciate that, in some embodiments, the processes described herein maybe re-ordered, omitted, or supplemented without departing from the scopeof the present disclosure. Moreover, it will be appreciated thatembodiments of method 300 may be performed using any suitable hardware,including the hardware described herein.

At 302, method 300 includes placing the metal-air battery into adischarge state. In some embodiments, placing the metal-air battery intoa discharge state may include completing an electrochemical circuit,where an electrical load is placed between an electrical ground and theanode, causing metal cations to be transported from the anode to thecathode through the battery separator where they are catalyticallyprocessed by the oxygen-reduction catalyst into a metal oxide.

At 304, method 300 includes obtaining the present, actual cathodetemperature (T_(actual)). In some embodiments, determining T_(actual)may include sensing the cathode temperature using a cathode temperaturesensor in thermal communication with the cathode. In some embodiments,T_(actual) may be estimated based on another sensed battery condition.

At 306, method 300 includes obtaining one or more battery operationalparameters associated with steady-state operation at cathode temperatureT_(actual). Some operational parameters may be measured. An electricalpotential difference between the anode and the cathode (i.e., batteryvoltage), a battery current, a battery power output (e.g., the amount ofpower available to an external load), a cathode temperature, and anambient temperature are non-limiting examples of measured operationalparameters. Other parameters, such as a battery discharge rate, abattery power delivery efficiency (e.g., amount of power available tothe external load relative to the total power generated by the battery,including the power consumed by the cathode), and a battery capacity orlifetime, may be estimated or calculated for a given cathode temperatureT_(actual).

At 308, method 300 determines that a boost in power output from thebattery is indicated. In some embodiments, boosting the power of thebattery may be indicated by variation or deviation in one or morebattery operation parameters during steady state operation. For example,a change in voltage across the power cell may indicate a decrease inpower generation within the power cell. Adjusting the cathodetemperature to trigger a power boost within the power cell maytemporarily extend steady state power output from the battery. Thus, insome embodiments, 308 may include, at 310, determining whether aselected operational parameter is different from a reference value forthat operational parameter at present cathode temperature T_(actual).Put another way, at 310, method 300 determines whether there is adeviation of more than an acceptable amount (e.g., a measurement orcalculation tolerance) between the actual value of a particularoperational parameter and some pre-selected value for that parameter.Optionally, the reference value may include a user- or aprogrammatically provided set point that is intended to govern operationof the battery with respect to at least that operational parameter. Inthe voltage example provided above, deviation of the observed power cellvoltage from a reference power cell voltage may trigger a power boost.As another example, a difference between a reference temperature (e.g.,ambient temperature or battery target operational temperature) and ameasured value for that temperature may also trigger a power boostcondition.

In some embodiments, a user-selected power boost may be triggered. Thus,in some embodiments, 308 may include, at 312, determining whether apower boost has been preselected. For example, a user may provide apower boost level or a power output level. In such embodiments,preselecting a power boost may include identifying deviations betweenobserved states and user-selected states, e.g., between observed poweroutput levels and user-selected power output levels.

At 314, method 300 includes identifying a cathode temperature that willgenerate a power boost, e.g., a power boost temperature (T_(pb)), ifsuch a temperature exists. Because the power used to adjust thetemperature of the cathode to the power boost temperature is generatedby the battery, the power capacity, or lifetime, of the battery may bepenalized on adjustment. The lifetime of a battery may refer to anysuitable duration, including the whole operational lifespan of thebattery (e.g., until the battery is exhausted) or some shorter specifiedoperational period (e.g., until a battery recharge interval). In someembodiments, projections of the battery lifetime penalty may begenerated based on historical battery operation data, preselectedbattery charging schedules, and/or present battery operationalconditions and parameters.

In some embodiments, identifying a power boost temperature may includeidentifying a power boost temperature at which value a projectedshort-term gain in power generation exceeds a projected long-termpenalty in battery lifetime. Put another way, if no power boost level isspecified, method 300 identifies a cathode temperature that will yield anet-positive value power boost for the battery. In some of suchembodiments, identifying a power-boosted temperature may includeutilizing a functional relationship between a positive value associatedwith the projected power boost and a negative value associated with theprojected battery penalty to evaluate the power benefit relative to thelifetime penalty. Alternatively, if a power boost has been preselected,identifying a power boost temperature may include identifying a powerboost temperature that will generate the selected power boost or poweroutput level, if that power boost temperature exists. For example, apower boost temperature may be identified at which the metal-air batterygenerates a selected power boost relative to a present battery powerlevel.

In some embodiments, identification of the power boost temperature mayinclude identifying one or more candidate power boost temperatures andsubsequently evaluating the candidate power boost temperature(s) todetermine which, if any, of the candidate temperatures will be used asthe power boost temperature. In some embodiments, candidate power boosttemperatures may be identified using one or more process control models.Process control models may include correlative relationships linkingcatalyst performance, cathode temperature, and power output. Suchrelationships may be based historic battery performance data,theoretical modeling, or empirical modeling.

In some embodiments, candidate power boost temperatures may be evaluatedwith respect to one or more temperature existence conditions to verifyoperability of the battery at a particular temperature. Put another way,a candidate power boost temperature that does not satisfy a specifiedtemperature existence condition may not be identified as a suitablepower boost temperature. If no candidate power boost temperaturesatisfies the existence condition(s), it may be determined that no powerboost temperature exists. In some embodiments, one or more of a batterydeactivation temperature condition, a battery over-temperaturecondition, a catalyst runaway temperature condition, and a catalystactivation temperature condition may be used to evaluate whether acandidate power boost temperature may be identified as the power boosttemperature.

Optionally, candidate power boost temperatures may be evaluated using aprocess search algorithm that identifies cathode temperatures yieldingpower boosts exceeding battery lifetime penalties or using anoptimization routine that seeks improvements in power output and/orlifetime penalties, among other characteristics of battery performance.For example, identifying a candidate power boost temperature may includeoptimizing (e.g., maximizing) the projected power boost withoutexceeding a specified value of the projected battery lifetime penalty.As another example, identifying a power boost temperature may includemaintaining a projected power boost at or above a specified value whileminimizing the projected battery lifetime penalty.

Upon identification of the power boost temperature, at 316 method 300determines whether the present, observed temperature of the cathode(T_(actual)) is different from the power boost temperature identified at314. If there is no difference between the observed cathode temperatureand the power boost cathode temperature, e.g., if no power boosttemperature is identified, method 300 advances to an evaluation ofbattery efficiency, described in more detail below and illustrated inFIG. 3B. If there is a difference in the temperatures, method 300advances to 318 and adjusts the temperature of the cathode to the powerboost temperature using power generated by the battery (e.g., usingcurrent drawn from the battery).

In some embodiments, a cathode temperature controller may use the powerboost temperature as a temperature set point to control the temperatureof the cathode. Altering the cathode temperature alters the catalyticactivity of the oxygen-reduction catalyst included in the cathode, and,in turn, the power generated by the battery. In one example, a heaterpowered by the battery and thermally coupled with the cathode may becontrolled to such a set point temperature to heat the catalyst andachieve a given power boost. Once the cathode reaches steady-stateoperation at the power boost temperature, method 300 obtains batteryoperational parameters for T_(pb) at 320. In some embodiments, the newlyobtained battery operational parameters may be stored along withearlier-obtained values to track the operational history for thebattery, refine a predictive operational model for the battery, and/orset a flag indicating an operational excursion for the battery.

Using power generated by the battery to adjust the temperature of thecathode may alter the efficiency with which the battery operates. Forexample, increasing cathode temperatures may increase the cathoderesistance, so that subsequent action to raise the cathode temperaturewith resistive heating may require greater amounts of power. In someembodiments, the temperature of the cathode may be adjusted, using powergenerated by the battery, so that the battery operating efficiencysatisfies one or more preselected efficiency criteria.

The efficiency (E) of a battery refers to, for a given temperature, thebattery power output relative to the power cell discharge rate (e.g.,power output by the power cell) at that temperature. In someembodiments, the efficiency may refer to an instantaneous efficiencydetermination. In some embodiments, efficiency may refer to batteryefficiency over a preselected time period (e.g., a battery operatinglife or operating interval).

In the embodiment shown in FIG. 3B, at 322, method 300 determines thatan adjustment to the battery operating efficiency is indicated. In someembodiments, an efficiency adjustment may be indicated by variation ordeviation in one or more battery operation parameters during steadystate operation. A variation between an observed value of a particularoperational parameter (e.g., power cell voltage, battery power output,battery target operational temperature, or ambient temperature) and apre-selected reference value for that parameter may trigger a change incathode temperature to affect an efficiency adjustment. In someembodiments, a user-selected or user-specified battery efficiency targetmay indicate an efficiency adjustment.

At 324, method 300 identifies a power efficient operating temperature(T_(eo)) for the cathode. In some embodiments, identifying T_(eo) mayinclude identifying a temperature at which the power cell generates aprojected efficient power boost that exceeds a projected batteryefficiency penalty, where the efficiency penalty represents a decreasein efficiency projected to result from operation at a differenttemperature. In some embodiments, projections of the battery efficiencypenalty may be generated based on historical battery operation data,and/or present battery operational conditions and parameters.Alternatively, if battery operating efficiency has been preselected,identifying a power efficient operating temperature may includeidentifying a temperature that will generate the selected efficiency, ifthat power efficient temperature exists. The projected efficient powerboost may be different from the power boost discussed above.

In some embodiments, identification of a power efficient temperature mayinclude identifying one or more candidate power efficient temperaturesand subsequently evaluating the candidate power efficient temperature(s)to determine which, if any, of the candidate temperatures will be usedas the power efficient temperature. In some embodiments, candidate powerefficient temperatures may be identified using one or more processcontrol models. Process control models may include correlativerelationships linking catalyst performance, cathode temperature, andpower output. Such relationships may be based on historic batteryperformance data, theoretical modeling, or empirical modeling.

In some embodiments, candidate power efficient temperatures may beevaluated with respect to one or more temperature existence conditionsto verify operability of the battery at a particular temperature. Putanother way, a candidate power efficient temperature that does notsatisfy a specified temperature existence condition may not beidentified as a suitable power efficient temperature. If no candidatepower efficient temperature satisfies the existence condition(s), it maybe determined that no power efficient temperature exists. In someembodiments, one or more of a battery deactivation temperaturecondition, a battery over-temperature condition, a catalyst runawaytemperature condition, and a catalyst activation temperature conditionmay be used to evaluate whether a candidate power efficient temperaturemay be identified as the power efficient temperature.

Optionally, candidate power efficient temperatures may be evaluatedusing a process search algorithm that identifies cathode temperaturesyielding power efficient boosts exceeding battery efficiency penaltiesor using an optimization routine that seeks improvements in power outputand/or efficiency penalties, among other characteristics of batteryperformance. For example, identifying a candidate power efficienttemperature may include optimizing (e.g., maximizing) the projectedpower efficient boost without exceeding a specified value of theprojected battery efficiency penalty. As another example, identifying apower efficient temperature may include maintaining a projected powerefficient boost at or above a specified value while minimizing theprojected battery efficiency penalty.

Upon identification of the power efficient temperature, at 326, method300 determines whether the present, observed temperature of the cathode(T_(actual)) is different from the power efficient temperature. If thereis no difference between the observed cathode temperature and the powerefficient cathode temperature (for example, if no power efficienttemperature is identified), method 300 returns to 308 (FIG. 3A). Ifthere is a difference in the temperatures, method 300 advances to 328and adjusts the temperature of the cathode to the power efficienttemperature using power generated by the battery.

In some embodiments, a cathode temperature controller may use the powerefficient temperature as a temperature set point to control thetemperature of the cathode. For example, a thermal electric coolerpowered by the battery and thermally coupled with the cathode may beused to lower the temperature of the catalyst to the power efficienttemperature. Once the cathode reaches steady-state operation at thepower efficient temperature, method 300 obtains the battery operationalparameters at 330. These operational parameters may be stored for otheruse. For example, stored parameters may be used to track the operationalhistory for the battery, refine a predictive operational model for thebattery, and/or set a flag indicating an operational excursion. Method300 then returns to 308 (FIG. 3A), and continues monitoring theoperational status of the battery.

It will be obvious to those having skill in the art that many changesmay be made to the details of the above-described embodiments withoutdeparting from the underlying principles of the invention. The scope ofthe present invention should, therefore, be determined only by thefollowing claims.

1. A metal-air battery, comprising: an electrochemically active anodethat emits electrons and metal cations during a discharge state; acathode that includes an oxygen-reduction catalyst to catalyticallyprocess the metal cations into a metal oxide; a battery separator thatelectrically isolates the anode from the cathode, the battery separatorbeing permeable to metal cations and positioned between the anode andthe cathode; a cathode temperature sensor that is thermally coupled withthe cathode and from which a present operating temperature of thecathode is obtained during the discharge state; a cathode temperaturecontroller that identifies a power-boosted operating temperature atwhich a projected power boost, relative to a present battery power,exceeds a projected battery penalty; and a temperature regulatorsupplied with current generated by the metal-air battery to adjust thecathode temperature from the present operating temperature to thepower-boosted operating temperature during the discharge state.
 2. Themetal-air battery of claim 1, further comprising an electrolyte, thebattery separator being permeable to the electrolyte.
 3. The metal-airbattery of claim 1, further comprising a heat transfer structurethermally connecting the temperature regulator with the cathode.
 4. Themetal-air battery of claim 3, in which the heat transfer structureincludes a solid phase thermal conductor.
 5. The metal-air battery ofclaim 3, in which the heat transfer structure includes a heat pipe. 6.The metal-air battery of claim 3, in which the heat transfer structureincludes a non-electrolyte fluid flow system.
 7. The metal-air batteryof claim 1, in which the projected battery penalty comprises a projectedpenalty over a specified time period.
 8. The metal-air battery of claim7, in which the specified time period corresponds to an operationallifetime of the battery.
 9. The metal-air battery of claim 7, in whichthe battery penalty comprises a battery efficiency over the time period.10. The metal-air battery of claim 1, in which the battery penaltycomprises an operational lifetime of the battery.
 11. The metal-airbattery of claim 1, wherein identifying a power-boosted temperaturecomprises utilization of a functional relationship between a positivevalue associated with the projected power boost and a negative valueassociated with the projected battery penalty.
 12. The metal-air batteryof claim 1, wherein identifying a power-boosted temperature comprisesmaximizing the projected power boost while not exceeding a specifiedvalue of the projected battery penalty.
 13. The metal-air battery ofclaim 1, wherein identifying a power-boosted temperature comprisesmaintaining the projected power boost at or above a specified valuewhile minimizing the projected battery penalty.
 14. The metal-airbattery of claim 1, in which the cathode temperature controlleridentifies a power-efficient operating temperature at which a projectedpower boost exceeds a projected battery efficiency penalty, and in whichthe temperature regulator uses current collected from the battery duringthe discharge state to adjust the temperature of the cathode topower-efficient operating temperature.
 15. The metal-air battery ofclaim 1, further comprising a resistive heater electrically connectedwith the temperature regulator and thermally coupled to the cathode toheat the cathode.
 16. The metal-air battery of claim 1, furthercomprising a thermoelectric cooler electrically connected with thetemperature regulator and thermally coupled to the cathode to cool thecathode.
 17. The metal-air battery of claim 1, further comprising arefrigeration unit electrically connected with the temperature regulatorand thermally coupled to the cathode to cool the cathode. 18-33.(canceled)
 34. A method for adjusting power generation by a metal-airbattery using current generated by the battery during battery discharge,the metal-air battery having a cathode containing an oxygen-reductioncatalyst and an anode separated from the cathode by anelectrolyte-permeable insulating battery separator, the methodcomprising: placing the metal-air battery in a discharge state; duringthe discharge state, collecting current from the battery; determining apresent temperature for the cathode; identifying a power-boostedtemperature at which a projected power boost, relative to a presentbattery power, exceeds a projected battery penalty; adjusting thetemperature of the cathode to the power-boosted temperature usingcurrent collected from the battery to alter catalytic activity of theoxygen-reduction catalyst.
 35. The method of claim 34, in which theprojected battery penalty includes a projected penalty over a specifiedtime period.
 36. The method of claim 35, in which the specified timeperiod corresponds to an operational lifetime of the battery.
 37. Themethod of claim 35, in which the battery penalty includes a batteryefficiency over the time period.
 38. The method of claim 34, in whichthe battery penalty includes an operational lifetime of the battery. 39.The method of claim 34, in which identifying a power-boosted temperatureincludes utilization of a functional relationship between a positivevalue associated with the projected power boost and a negative valueassociated with the projected battery penalty.
 40. The method of claim34, wherein identifying a power-boosted temperature comprises maximizingthe projected power boost while not exceeding a specified value of theprojected battery penalty.
 41. The method of claim 34, whereinidentifying a power-boosted temperature comprises maintaining theprojected power boost at or above a specified value while minimizing theprojected battery penalty.
 42. The method of claim 34, furthercomprising identifying the projected power boost using a positivecorrelation relating a power generation rate for the battery and aturnover frequency for the oxygen-reduction catalyst.
 43. The method ofclaim 34, further comprising identifying the projected battery lifetimepenalty using a negative correlation relating battery lifetime andcathode temperature.
 44. The method of claim 34, further comprising:identifying a power-efficient operating temperature at which a projectedpower boost exceeds a projected battery efficiency penalty; andadjusting the temperature of the cathode to the power-efficientoperating temperature.
 45. (canceled)
 46. The method of claim 34, inwhich determining the present cathode temperature includes sensing thecathode temperature using a cathode temperature sensor in thermalcommunication with the cathode.
 47. The method of claim 34, furthercomprising identifying one of the projected power boost or the projectedbattery lifetime or both of them using historical battery data.
 48. Themethod of claim 34, in which adjusting the cathode temperature includesheating the cathode using a resistive heater thermally coupled to thecathode.
 49. The method of claim 34, in which adjusting the cathodetemperature includes resistively heating the cathode by supplyingcurrent directly to the cathode.
 50. The method of claim 34, in whichadjusting the cathode temperature includes cooling the cathode using athermoelectric cooler thermally coupled to the cathode.
 51. The methodof claim 34, in which adjusting the cathode temperature includes coolingthe cathode using a refrigeration unit thermally coupled to the cathode.52-67. (canceled)
 68. A method for adjusting power generation by ametal-air battery using current generated by the battery during batterydischarge, the metal-air battery having a cathode containing anoxygen-reduction catalyst and an anode separated from the cathode by anelectrolyte-permeable insulating battery separator, the methodcomprising: placing the metal-air battery in a discharge state; duringthe discharge state, collecting current from the battery; determining apresent temperature for the cathode; identifying a power-boostedtemperature at which the metal-air battery generates a selected powerboost relative to a present battery power; adjusting the temperature ofthe cathode to the power-boosted temperature using current collectedfrom the battery to alter catalytic activity of the oxygen-reductioncatalyst.
 69. The method of claim 68, further comprising identifying theprojected power boost using a positive correlation relating a powergeneration rate for the battery and a turnover frequency for theoxygen-reduction catalyst.
 70. The method of claim 68, in which puttingthe metal-air battery into the discharge state includes: transportingmetal cations from the anode through the separator to the cathode; andat the cathode, catalytically processing the metal cations with theoxygen-reduction catalyst.
 71. The method of claim 68, furthercomprising: identifying a power-efficient operating temperature at whicha projected power boost exceeds a projected battery efficiency penalty;and adjusting the temperature of the cathode to the power-efficientoperating temperature.
 72. The method of claim 68, further comprisingidentifying a projected battery lifetime penalty at the power-boostedtemperature.
 73. The method of claim 68, in which determining thepresent cathode temperature includes sensing the cathode temperatureusing a cathode temperature sensor in thermal communication with thecathode.
 74. The method of claim 68, further comprising identifying theprojected power boost using historical battery data.
 75. The method ofclaim 68, in which adjusting the cathode temperature includes heatingthe cathode using a resistive heater thermally coupled to the cathode.76. The method of claim 68, in which adjusting the cathode temperatureincludes resistively heating the cathode by supplying current directlyto the cathode.
 77. The method of claim 68, in which adjusting thecathode temperature includes cooling the cathode using a thermoelectriccooler thermally coupled to the cathode.
 78. The method of claim 68, inwhich adjusting the cathode temperature includes cooling the cathodeusing a refrigeration unit thermally coupled to the cathode. 79-94.(canceled)